unable to access hive table in impala

Question

Unable to access hive table in Impala which has partition create on a date column. The data is inserted using dynamic partition column option. Now date datatype is not supported in impala. what i should do to access this table in impala. Is there is any option to create timestamp partition in hive if so what is method?

Answer 1

You can easily change column type. Two methods:

1) use alter table in Hive, change type to STRING, etc:

alter table table_name change column col_name col_name string cascade;

2) Alternatively you can change table type to EXTERNAL, drop and recreate with different column type then recover partitions:

ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
 DROP TABLE table_name;
 CREATE TABLE ... --change data type as desired
 location... --specify the same location;

After you created the table, use this command to create partitions metadata

MSCK [REPAIR] TABLE tablename;

The equivalent command on Amazon Elastic MapReduce (EMR)'s version of Hive is:

ALTER TABLE tablename RECOVER PARTITIONS;

This will add Hive partitions metadata. See manual here: RECOVER PARTITIONS